A spinning or twisting machine generally has a plurality of work stations. Each of the working stations is provided with a set of drafting rolls with at least three roll pairs in each set of drafting rolls. Each roll pair has a lower driven cylinder which passes through the machine in the longitudinal direction and is common to at least a number of work stations, and an upper roll individual to each work station.
In a spinning machine, e.g. a ring spinning machine, in which each work station is provided with a set of drafting rolls, after the roving on a roving bobbin has been used up, the empty roving bobbin must be replaced by a full roving bobbin. Then the roving must be threaded into the set of drafting rolls before a spinning process can begin again. The roving must be fed through the set of drafting rolls without halting the drive of the set of drafting rolls.
In the past this threading has customarily been performed with the set of drafting rolls open and with a supporting arm carrying the upper roll in a swung-up position.
The path of the roving into the set of drafting rolls is then clear so that the leading end of the roving is guided in by a roving guide normally upstream of the set of drafting rolls and runs through the entire set of drafting rolls.
However when the roving feed is started in this way usually the roving feed at the adjacent work station is disturbed since, as is usually the case, the upper rolls can be paired in so-called twin press rolls with the rolls of an adjacent station and are arranged, in pairs on the support arm.